How Much Would The GND Cost The Average Family

About a quarter-million bucks in the first five years?
I doubt there's any fact of the matter, it's such a crackpot scheme. How much would it cost to beat the Klingons? No fact of the matter.
Reminder: it's not a climate plan, and it's certainly not aimed at stopping the fictional climatopacalypse. It's a massive plan to implement a wish list of crackpot leftist social and economic preferences, disguised as a response to climate hysteria. No one would actually believed the climate stuff would adopt such a plan.
If you really believed the hype, you'd close the borders to prevent any migration from the third world to the first (which inflates people's carbon footprint by, like, an order of magnitude or something, build nuclear plants like they were going out of style, and just start shutting down roads and fossil-fuel-based electricity generation. You'd go to the Pubs and say: we will give you anything else you want if you'll just give us carbon reductions. You sure as hell wouldn't be wasting political capital on transgender bathrooms and whatnot.
And you certainly wouldn't be wasting resources on community gardens, "free" housing, "free" college, "free" food, "indigenous rights," and all the other nonsense in there.